1 box cake mix - we normally use yellow cake mix but it can be any flavor.
1 stick of butter (or margarine)
1 can of crushed pineapple (or sliced peaches)
Grease 9x13 pan and pour fruit - juice and all - in it.
Spread the box cake mix over it - try to make it evenly - and there is no need to mix it with the fruit.
cut and dot the butter over the cake mix.
Bake at 375 degrees for about 30 minutes.
It's easy, cheap and very good! You can put some vanilla ice cream on top to make it even better